Ask five people in India how this is calculated and you will get five confident answers, most of them slightly wrong. It is not their fault — the arithmetic is rarely explained, only the result is shown. So let us do it the other way round: first the logic, then the formula, then your own numbers in the compound interest.
Cover image slot — add a screenshot or illustration from Admin → Blog when it is ready.
Prefer to start with your own figures? Use the Compound Interest now, or continue for the formula and a worked example.
The logic, in plain language
Interest calculated on the initial principal, which also includes all of the accumulated interest from previous periods.
The formula behind it:
A = P(1 + r/n)^(nt)
| Symbol | What it means |
|---|---|
n |
Compounding frequency per year |
Nothing is rounded away quietly and nothing is assumed on your behalf. If a figure appears in the result, it came from something you entered.
Putting real figures through it
₹1 Lakh growing at 10% compounded annually for 20 years.
Change any one input and watch the result move — that sensitivity is the real lesson. It is far more useful than memorising a single outcome, because your own rate, tenure or contribution will never match the example exactly.
Using the Compound Interest, step by step
- Open the Compound Interest.
- Enter your figures. Use the ones on your statement, sanction letter or scheme document rather than a remembered number.
- Read the result card — the headline figure plus the breakdown that produced it.
- Adjust one input at a time to see what genuinely moves the outcome.
- Tap Download PDF to keep a copy of the calculation, with your inputs and assumptions printed on it.
The PDF takes a few seconds to build because it is a properly typeset report, not a screenshot. You will see a progress message while it is being prepared, and the download starts on its own.
Things worth knowing before you decide
- Higher compounding frequency increases the total return.
- Time is the biggest factor in compounding.
Where people usually slip up
- Ignoring the effect of the compounding frequency.
If you want to go a level deeper afterwards, read up on power of compounding. Both come up the moment you start comparing options seriously.